Fix build with Go 1.18 (darwin/arm64)

[ereslibre]

When trying to build reg with Go 1.18.4 (darwin/arm64), I'm getting the following error:

❯ go build
# golang.org/x/sys/unix
../../../.go/pkg/mod/golang.org/x/sys@v0.0.0-20190507160741-ecd444e8653b/unix/zsyscall_darwin_arm64.go:28:3: //go:linkname must refer to declared function or variable
../../../.go/pkg/mod/golang.org/x/sys@v0.0.0-20190507160741-ecd444e8653b/unix/zsyscall_darwin_arm64.go:43:3: //go:linkname must refer to declared function or variable
../../../.go/pkg/mod/golang.org/x/sys@v0.0.0-20190507160741-ecd444e8653b/unix/zsyscall_darwin_arm64.go:59:3: //go:linkname must refer to declared function or variable
../../../.go/pkg/mod/golang.org/x/sys@v0.0.0-20190507160741-ecd444e8653b/unix/zsyscall_darwin_arm64.go:75:3: //go:linkname must refer to declared function or variable
../../../.go/pkg/mod/golang.org/x/sys@v0.0.0-20190507160741-ecd444e8653b/unix/zsyscall_darwin_arm64.go:90:3: //go:linkname must refer to declared function or variable
../../../.go/pkg/mod/golang.org/x/sys@v0.0.0-20190507160741-ecd444e8653b/unix/zsyscall_darwin_arm64.go:105:3: //go:linkname must refer to declared function or variable
../../../.go/pkg/mod/golang.org/x/sys@v0.0.0-20190507160741-ecd444e8653b/unix/zsyscall_darwin_arm64.go:121:3: //go:linkname must refer to declared function or variable
../../../.go/pkg/mod/golang.org/x/sys@v0.0.0-20190507160741-ecd444e8653b/unix/zsyscall_darwin_arm64.go:136:3: //go:linkname must refer to declared function or variable
../../../.go/pkg/mod/golang.org/x/sys@v0.0.0-20190507160741-ecd444e8653b/unix/zsyscall_darwin_arm64.go:151:3: //go:linkname must refer to declared function or variable
../../../.go/pkg/mod/golang.org/x/sys@v0.0.0-20190507160741-ecd444e8653b/unix/zsyscall_darwin_arm64.go:166:3: //go:linkname must refer to declared function or variable
../../../.go/pkg/mod/golang.org/x/sys@v0.0.0-20190507160741-ecd444e8653b/unix/zsyscall_darwin_arm64.go:166:3: too many errors

This is related to golang/go#51706, and is fixed by bumping golang.org/x/sys.

This PR bumps this dependency so that reg builds with Go 1.18.

[tkchk]

Can confirm. This PR fixes build errors

[dustin-decker]

Also implemented in #224 along with updating the installation command